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Influence of hazardous EM fields on large objects
Klučka, Jaroslav ; Kovács, Peter (referee) ; Řezníček, Zdeněk (advisor)
This bachelor thesis deals with simulation of influences of electromagnetic field on an aircraft via computer program PAM-CEM. The aim of the simulation is verification of conditions for placing equipment and cables in chosen places. There were chosen two outer interfering electromagnetic fields: High Intensity Radiated Fields HIRF and a lightning bolt. During the simulation of HIRF, the plane was radiated by outer electromagnetic field. The decomposition of inner electromagnetic field was monitored during the exposure. Then, the electrical intensity was measured in three places, where the location of susceptible electronical devices was predicted. During the simulation of lightning bolt only indirect effects were taken into consideration. Current impulse was implemented into the skin of the aircraft and the decomposition of surface current was monitored.
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Surface Plasmon Resonances on Colloidal Nanoparticles
Beránek, Jiří ; Brzobohatý,, Oto (referee) ; Šikola, Tomáš (advisor)
The presented diploma thesis is focused on the Localized Surface Plasmons (LSP). The far-field optical response of the colloidal solutions of gold nanoparticles caused by LSP was investigated and compared with the numerical calculations. For the simulations, the Discrete Dipole Approximation (DDA) and Finite-Difference Time Domain (FDTD) techniques were employed. In particular, the shape and size effects of spherical particles and nanorods were studied. The simulations performed by both methods are in a good agreement for the spheres. For the nanorods, the resonance was found to be affected markedly by their geometry. Also, broader resonance peaks were found. This effect was assigned to the sample size distribution and its influence is discussed by comparing the simulations with experiments. In addition, synthesis of nanorods was carried out as well. Finally, the results on the study of optical properties of silver clusters formed under equilibrium conditions are presented.
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Numerical optimization of absorption of mid-infrared plasmonic structures
Kulič, Martin ; Křápek, Vlastimil (referee) ; Kvapil, Michal (advisor)
Plasmonic nanostructures have a long and rich history in spectroscopy and sensing. First, we look at the history and applications of plasmonic structures and we discuss the parameters that influence the enhancement of various methods. Then the influence of plasmonic nanostructures on energy absorption in a thin layer of silicon oxide, silicon nitride and silicon-rich oxynitride of varying thickness is probed using Lumerical FDTD Solutions software. The last part of this thesis focuses on numerical demonstration of application of plasmonic antennas in spectroscopy.
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Rigorous Simulation of Light Interaction with Cells
Dršata, Martin ; Kalousek, Radek (referee) ; Petráček, Jiří (advisor)
This bachelor thesis focuses on rigorous simulations of light scattering by living cells. The first part is dedicated to brief introduction to the given issues and the basic description of the often used computational methods and models of cell structures. Experimental part deals with light scattering simulations using the finite difference time domain method (FDTD). Models of spherical cell and red blood cell are used in these simulations. The aim of the calculations for the first model is to assess the accuracy of the FDTD method with respect to the analytical method using Mie theory of light scattering.
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Modeling Sound Field in Closed Space at Low Frequencies
Hořák, Pavel ; Kiska, Tomáš (referee) ; Schimmel, Jiří (advisor)
This diploma thesis deals with issues of low frequency acoustics and simulation. In this work the FTDT method of simulation is used. Measuring and simulation are focused on live-sound system and are evaluated using basic sound system optimisation techniques. Main output of this work is verification of basic low-frequency acoustics principles using simulation and measuring.
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Loudspeaker System for Reproduction of Low Frequencies with Directional Radiation
Skvaril, Šimon ; Husník, Libor (referee) ; Schimmel, Jiří (advisor)
Final product of this work is design of speaker baffle which will have directional radiation at low frequencies. In the course of the work, propagation of sound waves and their beaviour at obstacles are described. The computational method FDTD and the K-wave toolkit for MATLAB, which uses this method, are described. In MATLAB a virtual model of speaker baffle is created and proposed solution is verified. Next step is creation of scaled model of speaker baffle on which agreement of theoretical computations with real-world measurment is verified. Final step is creation of prototype of speaker baffle,, whose parameters are measured, including polar response.
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Plasmonic Resonant Antennas
Kvapil, Michal ; Dub, Petr (referee) ; Tomanec, Ondřej (advisor)
In the first part, using of nano- and microparticles in the plasmonics as well as the possibility of measurement resonant spectra of metallic nanostructures by photoluminescence are discussed. The main part of the work is focused on testing the possibility of using software Lumerical FDTD Solution 5.1.3 to simulate near field enhancement in the vinicity of plasmonic resonant antennas. Finally the results of simulations and analytical computation are confronted.
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Modelling of photonic structures using Finite-difference time-domain method
Procházka, Pavel ; Kalousek, Radek (referee) ; Petráček, Jiří (advisor)
This bachelor thesis is focused on the basic description of the finite-difference time-domain method (FDTD) which serves to the numerical solution of Maxwell's equations. FDTD is very used today because during one calculation it is possible to obtain results in wide frequency spectrum. The thesis contains deduction of \mbox{equations} for description of this method and algorithm of calculation. The main goals of this thesis are the identification of the free Meep software, which is constructed for this calculations, and understanding of its properties. Most of Meep functions are described on three examples in the second part of bachelor thesis.
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Excitation and Detection of Plasmon Polaritons
Šustr, Libor ; Schmidt, Eduard (referee) ; Kalousek, Radek (advisor)
The diploma thesis is aimed to excitation and detection of surface plasmon polaritons by visible light. First of all, we will briefly remind some basic principles like waves, electromagnetic wave, light on the interface and optical properties of metals. By using these principles we show presence of surface plasmon polaritons states. After the explanation of their properties there will be clearly visible reasons for aplications of the special excitationand detection methods. We will describe especially the prism coupling, periodic grating coupling and SNOM. Two last sections deal with computer simulations and experiments related to these methods. This means we can exemplify some knowledge presented in previous chapters. Results of simulations are compared with the experiment where we study the excitations of surface plasmon polaritons by periodic grating on aluminium surface.
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Localized Surface Plasmons: Principles and Application
Kvapil, Michal ; Schmidt, Eduard (referee) ; Šikola, Tomáš (advisor)
The diploma thesis deals with plasmonic nanostructures for visible eventually near-infrared region of electromagnetic spectrum. At first, there are discussed basic terms which are necessary for description of plasmonic nanostructures and their properties. Then the resonant properties of gold nanoantennas on a fused silica substrate and in proximity of nanocrystalline diamond are addressed. FDTD simulations are used for an assesment of resonant properties and local electric field enhancement of these nanostructures. Possible manufacturing methods of the antennas and techniques for the measurement of their properties are mentioned at the end of the thesis.
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